Late harvest wine

Botrytis cinerea is a fungus that affects many wine grapes and causes them to shrivel into moldy raisins.

As the mold penetrates the skin its spores begin to germinate, causing the water inside to evaporate and the grape to dehydrate.

In some years desiccation may occur leaving tiny amount of sweet liquor like juice within the grape.

[1] The infection rate of botrytis is sporadic with vines and bunches achieving full rottenness at different times.

This requires harvest workers to go through the vineyards several times between October and November to hand-pick the full rotted grapes.

As the grapes are pressed, the frozen water crystals [6] are eliminated leaving the highly concentrated sugar behind.